Die for forming insulators.



PATBNTED DEC. 18, 1906.

P. M. LOCKS.

DIE FOR FORMING INSULATORS. APPLICATION rmm NOV. 24, 1906.

UNITED STATES PATENT OFFICE.

Application filed November 24,1905. Serial No. 288.975.

To all 1071 0171, it may concern.-

Be it known that I, FRED M. Looxn, of Victor, in the county of Ontario, in the State of NGW YOI'k, have invented new and useful Improvements in Dies for Forming Insulators, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain improvements in dies for forming the interior contours of hollow plastic bodies, and refers more particularly to the means for forming the interior chambers and petticoats of insulators, as an improvement upon my Patent No. 716,343, December 16, 1902, in which one of the essential purposes is to provide for the escape and reentrance of air through the die during its entrance into or withdrawal from the plastic material. In this class of apparatus a die is uniformly and progressively advanced under a rotary motion into and out of the plastic material, and in my patent referred to I have provided the die with a series of apertures for the escape and a valved inlet for the reentrance of air from and to the intervening space between the die and the plastic body; but in my present invention I have sought to simplify and at the same time increase the elliciency of the die by providing it with an annular air-space leading from the deepest chamber in the die to the atmosphere, so that the escape and reentrance of air will be uniformly distributed over practically the entire area or surface of the plastic material which is being formed.

In other words, my object is to cause the air to follow more closely along the sides of the forming surface or chambers of the die between such surface and the material into which the die enters, whereby the air finds a more direct escape to prevent air-holes and also enters more directly between the die and plastic material for the purpose of freeing the die from any adhering matter as said die 1S withdrawn therefrom.

Other objects and uses will be brought out in the following description.

In the drawings, Figure 1 is an elevation of my improved die. Fig. 2 is a longitudinal vertical sectional view, partly in elevation, of the die seen in Fig. 1. Fig. 3 is a horizontal section taken on line 3 3, Fig. 2, showing the central stem and concentric flange which sur-.

rounds the same.

As seen in the drawings, this die consists, and is the first to recede from the plastic ma- 11o Specification of Letters Patent.

Patented Dec. 18, 1906.

essentially, of the central screw-threaded stem 1 and a concentric flange 2 surrounding the central stem, but spaced apart therefrom, forming the intervening annular chamber 3, which terminates at its base in a constricted annular air-passage 4, opening to at mosphere.

The central stem 1 is extended in opposite directions some distance beyond the opposite ends of the chamber 3 and flange 2 the end opposite to that upon which the threads, as 5, are formed being provided with a socket 6, adapted to receive any suitable shaft or rotating member, by which rotary axial motion may be imparted to the die in the manner set forth in my patent previously referred to or in any other suitable manner, not necessary to herein illustrate or describe. The flange 2 is united to the extension, as 7, of the stem 1, above the annular air-passage 4, by two or more radial arms 8, thereby leaving a clear open space above the flange 2 and annular space 4 for communication with the chamber 3 through said annular space 4. It is now obvious that if this die is advanced progressively and uniformly under a rotary motion into a body of plastic material the threaded stem 1 will form a central threaded socket, while the flange 2 will form an annular chamber in said plastic material, leaving a petticoat of the same material formed by the walls of the chamber 3, during which operation the air between the contiguous faces of the die and plastic body will be forced upwardly and find free exit through the annular passage 4 to the atmosphere. On the other hand,when the die is uniformly and progressively Withdrawn under the same rotary motion, but in the reverse direction, from the plastic material the air will readily enter through the annular passage 4 and follow along the contiguous surface of the die and plastic material, thereby relieving any tendency to create a vacuum, which would operate to destroy symmetry and smoothness of the contour of the plastic material previously formed. 'In other words, by creating a narrow annular air-space at the base of the chamber 3 air is allowed to escape and reenter at all points in the circumference of the central stem land inner circumference of the flange 2, thereby assuring an even distribution of the air and a direct exit and reentrance at the base of the chamber 3, which is the last to fill up with having a socket at. one end and threaded fora terial during the formation ofthejinsulator or other article.

What I claim is 1. In a mold for plastic material, a stock having a threaded terminal, an annular mem ber surrounding said stock intermediate its ends and s aced slightly therefrom and With an integra annular rib depending from said annular member and spaced from the, threaded portion of said stock, and a plurality of braces integral with said stock and annular member and connecting: the annular member to the stock.

2. In a mold for plastic material, a stock portion of its length at the other end, an annular member surrounding said stock intermediate its ends and spaced slightly therefrom and with an integral depending annular rib spaced from said stock, and a plurality of 20 FRED M. @LOCKE.

\Vitnesses: I

G. T. CURTIS, W. W; HUBBARD. 

